Karst regions
The major karst areas of North America and what lives in them

Subterranean fauna follows rock rather than borders. A karst region is often the more meaningful unit: species are shared along a limestone belt in ways they are not shared across a state line.

Appalachians 329 species 328 obligate subterranean 210 ranked G1 or G2 Black Hills 2 species 2 obligate subterranean 1 ranked G1 or G2 Driftless Area 13 species 13 obligate subterranean 5 ranked G1 or G2 Edwards Plateau and Balcones 257 species 257 obligate subterranean 147 ranked G1 or G2 Florida Lime Sinks 34 species 33 obligate subterranean 30 ranked G1 or G2 Guadalupe Mountains 16 species 16 obligate subterranean 12 ranked G1 or G2 Hawaii 60 species 60 obligate subterranean 44 ranked G1 or G2 Interior Low Plateau 439 species 438 obligate subterranean 288 ranked G1 or G2 Mother Lode 27 species 27 obligate subterranean 23 ranked G1 or G2 Other 304 species 304 obligate subterranean 164 ranked G1 or G2 Ozarks 122 species 121 obligate subterranean 46 ranked G1 or G2

Many species are recorded from more than one region, so these counts add up to more than the total number of species.